/**
 * Classname: item_c
 * Package: PACKAGE_NAME
 * Description:
 *
 * @Author Alex Liang
 * @Create 2023/10/8 19:26
 * @Version 1.0
 */

public class Base {
    public String show(Base obj){
        return ("A");
    }
}
class  Derived extends Base{
    public String show(Derived obj){
        return ("B");
    }
    public String show(Base obj){
        return ("C");
    }
}
class Demo{
    public static void main(String[] args) {
        Base a = new Derived();
        Derived b = new Derived();
        System.out.println(a.show(b));
        System.out.println(b.show(b));
    }
}